bone up on 钻研；加紧练习；加紧学习

【例句】
Jim checked out some books from the library in order to bone up on physics.
吉姆从图书馆借了一些书，以便钻研物理学。

She has no time to go shopping with her friends, because she needs to bone up on her math.
她没有时间和朋友一些逛街，因为要加紧学习数学。